Switching mechanism



Oct. 12, 1943- a. R. STIBITZ SWITCHING MECHANISM Filed May 31, 1941 1 2 Sheets-Sheet 1 FIG/ INVENTOR G. R. S T/B/ T2 ATTORNE Oct. 12, 1943. G. R. STIBITZ SWITCHING MECHANISM Filed May 31, 1941 2 Sheets-Sheet 2 Z RT V S WR 4 G a H nr nfl n" a; b m 3 k w m n m 1 m z 5 r. l WV 5 M p T rk \mw W m ATTORNEY WWW! of the connections Patented Oct. 12, 1943 SWVITCHING MECHANISM George R. Stibitz, Boonton, Telephone Laboratories,

N. J., assignor to Bell Incorporated, New

York, N. Y., a corporation of New York Application May '31, 1941, Serial No. 396,081

9 Claims.

This invention relates to switching mechanisms and particularly to mechanisms employed to establish electrical connections, such as telephone or other communication connections.

An object is to simplify the operating characteristics and reduce the cost of such mechanisms as well as to increase the utility thereof.

Heretofore switching devices have been used in which one group of vertical or select coils crosses another group of horizontal or holding coils and in which contact elements are located at the intersecting points of said two groups of coils. The arrangement is such that the energization of one or more select coils followed by the energization of one or more holding coils causes electromagnetic flux produced by both groups of energized coils to act in unison on the contacts at the corresponding intersecting points to establish corresponding connections between the contacts at said crosspoints. In these types of switching devices it becomes necessary after a connection at a crosspoint of a select coil and a holding coil to deenergize the select coil and to reduce the energization of the holding coil to a point where the remaining percentage of energization of this holding coil will be suflicient to hold the connection established while on the other hand it must not be of such high value as to interfere with subsequent selections of contacts at other crosspoints or cause false connections at any of the other intersecting points where the partly energized holding coil is crossed by the select coils.

It is a feature of the present invention to provide a switching device of this type in which after connections have been established at one or more crosspoints by the energization of select coils and holding coils, the energization of the holding coils need not be reduced but may remain fully energized to hold the established connection without interfering with subsequent connections and thus marginal values of the energizing currents are avoided.

It is a special feature of the applicants device to provide at each intersecting point a contact mechanism comprising magnetic elements associated with the contact elements whereby the establishing of connections at crosspoints is accomplished by the energizing and deenergizing of both select coils and holding coils in certain sequences and combinations, and energizing and maintaining fully energized only the holding coils employed for the maintaining desired and made. For exhas been established ample, if a connection is to be established at the crosspoint of a certain select coil and a certain holding coil, all the holding coils except the one which will be involved in the establishing of the desired connection will first be energized followed by the energization of the select coil involved in the establishing of this desired connection, whereupon the holding coil involved in this desired connection will be energized and the remaining holding coils and the energized select coil will be deenergized. Thus only one holding coil will remain energized to hold the established connection without reducing the energizing current for said holding coil. By this connecting mechanism and these sequences of operations of the coils, false operations of the switching mechanism and marginal characteristics of the energizing current are avoided.

The invention has been illustrated in the accompanying drawings in which:

Fig. 1 shows a simplified perspective of one embodiment of the applicants invention;

Figs. 2 and 3 show similar perspective views of two modified forms of the applicant's invention;

Fig. 4 shows a simplified diagrammatic representation of the applicant's invention with a plurality of select and holding coils and connecting mechanisms at the crosspoints.

Referring now to Fig. 1, one select coil I0 and one holding coil ll only have been shown with a contacting mechanism arranged at the cross point of these coils. It is to be understood, of course, that similar contacting mechanisms may be applied at crosspoints where a plurality of select coils cross a plurality of corresponding holding coils. The contacting mechanism at the crosspoint shown consists of an upper magnetic plate l2 and a lower corresponding magnetic plate l3 with an intermediate magnetic contact spring I4. These elements may be assembled together as shown at the rear of the structure at H with the spring l4 insulated from the plates l2 and I3. It should be noted that the plate 12 is in the form of a rectangular frame with the front member split to form two opposing members l5 and I6 and with the side members 18 and I9 located outside of the coil H and that the plate I3 is similarly shaped with two opposing front members 20 and 2| and with the side members 22 and 23 outside of said coil I I. However, these side members 22 and 23 are bent to form depressions at and 25 to permit one side of coil H] to pass between these side members and the side members It! and IS. The spring .grammatic form M is tensioned to make contact with the members l5 and 5.

In the modification shown in Fig. 2 only two intersecting coils, namely, a select coil 26 and a holding coil 21 have been illustrated with a contact mechanism at the cross-point. The contacting mechanism may be arranged with an upper magnetic plate 29, a lower magnetic plate 38 and an intermediate magnetic contact spring iii. The plate 29 has its side member 32 located on the left-hand side of the coil 2'! and is bent over and above the coil 25 and then downwardly and then terminating in a member 33 extending towards the right to normally make contact with the spring 3|. The plate 38 has its side member 34 extending forwardly to pass through the coil 26 and then terminating in a member at extending towards the left adjacent the spring 3| to form a connection therewith when the mechanism is operated. The plates 29 and 88 are assembled with spring t l at 31 but insulated therefrom.

In Fig. 3 a similar arrangement has been pro- 'vided at the crosspoints of intersecting coils except that in this case two independent connections may be established at each crosspoint of a select'coil and a holding coil. In this figure one holding coil All has been shown and two select coils 4| and 42. At the rear of this structure a series of horizontally located magnetic connecting plates are provided consisting of an upper plate A3 and below this plate but insulated from each other spring plate 6, plate 45, plate ifi, spring plate 41 and plate it. The contact mechanism, at the crosspoint of coils All and 42 and extending from these plates at the rear of the structure, may consist of a member 58 extending from the upper plate 43 and terminating in a member 5| extending towards the left, a spring member 52 extending from spring plate' 46, a member 53 extending from plate &5 and terminating in a member extending towards the right, a member extending from plate 48 and terminating in a member 55 extendingtoward the left, a spring member 51 extending from spring plate ll and a member 58 extending from plate 48 and'terminating-in a member 59 extending toward the right. Themembers 54 and 59 are surrounded bythe coil 42 while coil 40 surrounds all of the members 5|, 52, 54, 56, Hand 59. Spring member 52 is normally tensioned to connect with the member 5| and spring 5? is normally tensioned to connect with member 56. When this contacting mechanism is operated by the energization of coils as will hereinafter be described, the spring member from member 5| and connected to member 5a and spring member 51 is disconnected from .member 56 and connected with member 59.

Thus two separate connections maybe established at each crosspoint. A similarly arranged contacting mechanism is provided at each crosspoint of a select coil and a holding coil.

I In Fig. 4 an arrangement of four horizontally .located select coils and four vertically located holding coils have been shown in diawith the contact mechanisms at the crosspoints 65 and 66 only having been indicated for the purpose of describing how connections may be established at crosspoints in accordance with the applicants invention. The

particular contact mechanism indicated would be the one disclosed in Fig. 1. It should be un- 52 is disconnected derstood that the contact mechanism of Figs. 2 or 3 could be substituted for the one shown without departing from the spirit of the invention. Each select coil and each holding coil is provided with an operating circuit including a source of current and contact elements as shown so that the energizing of a coil may be accomplished by the closing of the associated circuit by the associated contact elements and so that the deenergization or a coil may be accomplished by the opening of the associated circuit by the associated contact elements. If it is assumed that a connection is to be established at the crosspoint b5, the first operation taking place is that the holding coils El, 63 and as are energized by the closing of the associated circuits. The energization of these holding coils will magnetize the plates I2 and |3 associated with these coils to maintain the contact spring it in connection with members l5 and it at the points where these coils cross the selectcoils. That is, while the members 20 and iii are magnetized to the same Values as members I5 and i6, inasmuch as the spring M is already in contact with members it and Hi and the members 26 and 2| are further away from the contact spring Hi, this spring will remain connected to the members i5 and 55. If now the select coil is energized by the closing of the associated circuit, it will be noted that this coil will only magnetize plates 13 as these plates only and not the plates l2 are surrounded by coil H! as shown in Fig. 1. This will have the effect that the members and 2| will attract the spring i4 away from the members it: and it and cause it to make a contact with these members and 2| at the crosspoint only, whereas this select coil ii! will not cause the springs Hi to be attracted by the members 20 and 28 at the crosspoints where this select coil crosses the holding coils 61, t8 and 69, as at these crosspoints the springs M are already held latter holding coils.

in contact with members I5 and M5 by these If the holding coil H is energized by the closing of the associated circuit, this coil will at the crosspoint 65 magnetize the members 20 and 2| to maintain the spring M in connection with these members 20 and 2| while at the crosspoints where coil H crosses the remaining select coils, the springs It will be held attractedby the members |5 and |6.. The coil iii may now be deenergized by the opening of the associated circuit as it is no longer necessary for this'coil to control the spring M at the crosspoint '85 and also the coils 5'1, 8% and 69 may thereafter be deenergized by the opening of the associated circuits as it is no longer neces- 'wlll also be noted that when subsequent connections are desired at any crosspoint where any other holding coils cross any of the select coils, this may be done without interfering with .thealready established connection or be interfered with by the fact that the holding coil isfully energized. For example, if a connectlon. is now desired at the crosspoint 66', holding coils 61 and 69 will be energized, coil 1| being already energized. The select coil 12 will then be energized to cause the spring M to be attracted by the members and 2| at the cross-- point 66. The holding coil 68 will then be energized to hold this connection at crosspoint 66 whereupon the select coil 12 will be deenergized followed by the deenergization of coils 61 and 69. Thusth'e previous fully energized condition of holding coil 1| will have no distributing influence during thissucceeding selection at crosspoint 66.

If it is desiredto establish simultaneous connections at a plurality of crosspoints where a holding coil crosses the select coils, this may be done without interference with previou connections. For example, if it is desired to establish connections at cro-sspoints 13 and 14 assuming that connections have previously been established at crosspoints 65 and 66, the holding coil 69 will beenergized first, then select coils 10 and 15 and then holding coil 61, whereupon select coils 10 and 15 are deenergized followed by the deenergization of holding coil 69.

It should be observed that, while the intersecting coils and associated contact mechanisms at the crosspoints of the structures shown in Figs.

2 and 3 are placed in somewhat different relationships from the corresponding parts of the structure shown in Fig. l, the method of selecting and operating the mechanism are the same. In Fig. 2, for example, coil 26 is a select coil and coil 21 is a holding coil. Coil 21 will therefore when energized either retain contact 3| inconnection with member 33 if coil 26 has not been previously energized or in the case coil 26 has been energized to cause contact 31 to connect with member 38, coil 21 will maintain this latter connection. In Fig. 3 coil 42 is the select coil and coil is a holding coil so that the coil MI-Will cause contacts 52 and 51 to remain connected respectively with contact members 5| and 51 or maintain them connected with members 54 and 59.

What is claimed is:

1. A switching device comprising a first and a second group of coils arranged to cross each other, a circuit controlling mechanism at each intersecting point of said two groups of coils including an upper and a lower stationary contact element and a movable contact spring intermediate said stationary elements normally connected to the upper stationary element, and arranged so that on the energization of all but one of the coils in th first group, the movable contact springs of the contact mechanisms associated with said coils are magnetically held in contact with the upper stationary elements, so that on the following energization of one of the coils of the second group the movable contact spring of the circuit controlling mechanism at the crosspoint of the latter coil and the coil of the first group not energized, is magnetically attracted tothe associated lower contact element, said first energized coils of the first group and the energized coil of the second group being then deenergized While the coil of the first group remaining energized maintains the established connection between said movable contact spring and the lower contact element.

2.- A switching device comprising a first and sccondgroup of coils arrangedto cross each-other,

a circuit controlling mechanismv at each inten secting point of said two groups of coils comprising an upper magnetic contact plate, an in termediate magnetic contact spring normally connected to said upper plate and a lower magnetic contact platen. normally disconnected from said spring, said plates and spring at each cross-- point being so arranged in relation: to the asso ciated coils that on coil will, when energized, attract the intermediate spring to thelower plate and the other coil when energized will maintain the intermediate'spring attracted to either plate, means for energizing all but one'of the coils in the first group for energizing one of the coils of the second group andfor energizing said re-' maining coil in the first group and for then deenergizing said coil energized in the second group and for deenergizing said first-mentioned coils in the first group for actuating the circuit con-- trolling mechanism at' the crosspoint of said coil in the second group and the coil in the first groupwhich remains energized to disconnect the intermediate spring from the upper plate and connects it to the lower plate and maintain it connected to the lower plate as long as the coil in the first group remains energized.

3. A switching device comprising afirstand' secondgroup of coils, arranged to cross each other, a circuit controlling mechanism. at each intersecting point of said two groups of coils each comprising sets of contacting means, each set comprising an upper magnetic element, alower magnetic element and an intermediate magnetic spring normally connected with theupper" element, said sets at each crosspointbeing so arranged in relation to the associated coils that the coil in the second group when energized will. attract the intermediate magnetic springs to contact with the associated lower magnetic ele. ments and the coil in the first group \vhen ener gized will maintain the intermediate magnetic springs connected to. either the upper or the. lower associatedmagnetic elements, means for energizing all but one of the coils of the first group, forenergizing one of the coils in the sec ond group, for energizing said remaining coil in thefirst group, for deenergizing said coil energized in the second group and for cleenergizing, said first-mentioned coils in the first group for actuatin the circuit controlling mechanism at the crosspoint of said coil energized in the second group and the coil in the first group which remains energized to disconnect the intermediate springs from the respective upper elements and connect them with the respective lower elements and maintain said connections as long as said coilin the first group remains energized;

4. A switching device comprising a group of select coils and group of holding coils, arranged to cross each other, a circuit controlling mechanism at each intersecting point of said two groups of coils-including an upper. and a lower stationary contactv element and a movable contact spring intermediate said stationary elements normally connected with the upper stationary element and arranged so that on the energiza tion of all but one of the holding coils, the movable contact springs of the contact mechanisms associated with said holding coils are magnetically held in connection with the upper station ary elements and so that on the following energization of one of the select coils themovable contact spring of the circuit controlling mechanism at. th crosspoint of this select coil andthe holding. coil not energized .ismagnetically attracted to the associated lower contact element, so that on a subsequent energization of the remaining holding coil, the deenergization of the previously energized holding coils and the energized select coil, the remaining energized holding coil will maintain the established connection between said movable contact spring and lower contact element.

. 5. A switching device comprising a group of select coils and a group of holding coils arranged to cross each other, a circuit controlling mechanism at each intersecting point of said two groups of coils each mechanism including two stationary contact elements and an intermediate movable contact spring normally connected to the upper stationary element and so positioned in relation to the coils that a select coil associated with a row of circuit controlling mecha nisms will when energized magnetize the lower stationary elements and the intermediate movable contact springs to move said contact springs from contact with the upper elements and connect them with the lower elements while when a holding coil is energized all the circuit controlling mechanisms associated with this coil are so arranged that the intermediate springs will be held attracted to the-upper or lower stationary contact elements depending on their position prior to the energization of said holding coil, said circuit controlling mechanisms being thereby operative by the energization of all but one holding coil, a plurality of select coils and then the remaining holding coil followed by the deenergization of said plurality of select coils and the deenergization of the first-mentioned holding coils to respond at the crosspoints of said last-mentioned holding coil and said plurality of select coils to establish circuit changes and to maintain these changes until the last-mentioned holding coil is deenergized.

6. A switching device comprising a group of select coils, a group of holding coils arranged to cross each other to form openings where the coils of one group cross the coils of the other group, a plurality of magnetic contact elements in each opening consisting of an upper contact element, an intermediate contact spring and a lower contact element so arranged in relation'to the associated coils that on the energization of a select coil the associated intermediate contact springs are attracted by the associated lower contact elements and when a holding coil is energized the associated intermediate contact springs are maintained connected with the upper contact element if they have not been shifted and maintained connected with the lower contact elements if they have been shifted, and means for energizing all but one of said holding coils for energizing one or more select coils for energizing the remaining holding coil and for then deenergizing said one or more select coils and for deenergizing said first-mentioned holding coils to create flux in said openings to cause the magnetic contact elements in the openings formed by the holding coil remaining energized and said one or more select coils to shift, so that the connections between the upper contact elements and the intermediate contact springs are opened and the connections between the lower contact elements and the intermediate contact springs are closed and maintained as long as said holding coil is maintained energized,

7. A switching device comprising a group of select coils and a group of holding coils, said groups of coils being arranged to cross each vother to form an opening where a coil of one group crosses the coil of the other group, a plurality of magnetic contact elements in each opening,

one of the contact elements in each opening connected normally to a second and a third contact element while a fourth and a fifth Contact element are normally separated from the other elements, means for energizing all but one of the holding coils to maintain the elements surrounded by said holding coils in normal position, means for energizing any plurality of select coils to actuate the first element to disconnect itself from the second and third elements and engage the fourth and fifth elements in each of the openings surrounded by said plurality of select coils and the holding coil not energized, means for energizing said remaining holding coil to maintain the elements in the openings surrounded by said energized select coils and said lastmentioned holding coil to maintain the first element in connection with the fourth and fifth elements in said openings, while the select coils energized may be deenergized and the first energized holding coils may be deenergized to enable any subsequent connective changes to take place and to be maintained simultaneously at a plurality of openings surrounded by any other holding coils and any select coils when energized and deenergized in the same manner without having the energization of a previously energized holding coil interfering with the establishing of said subsequent connective changes.

8. A switching device comprising a first and a second group of coils arranged to cross each other, a circuit controlling mechanism at each intersecting point of said two groups of coils including an upper and a lower stationary contact element and an intermediate movable contact spring normally connected with the upper stationary contact element, a circuit for each coil, a source of current in each said circuit, a contact element in each said circuit for closing and opening the associated circuit to energize and deenergize the associated coil, said circuit controlling mechanism'being so arranged that on the closing of all but one of the circuits for the coils of the first group, the closing of the circuit for any one of the coils of the second group, the closing of the circuit for the remaining coil of the first group, the opening of the circuits for the first energized coils in the first group and the energized coil in the second group and the maintaining of the circuit for the last energized coil in the first group closed, circuit changes are made in the circuit controlling mechanism at the intersecting point of the energized coil of the first group and the coilin the second group that was deenergized, said circuit changes consisting in the intermediate movable spring being attracted by the lower stationary contact element on the energization of said coil in the second group and being maintained attracted solely by the energized condition of said coil of the first group.

9. A switching device comprising a first and a second group of coils arranged to cross each other, a circuit controlling mechanism at each intersecting point of said ,two groups of coils comprising an upper magnetic element, a lower magnetic element and an intermediate magnetic spring normally connected with the upper magnetic element, a circuit for each coil, a source of current in each of said circuits, a contact element in each of said circuits for the closing and opening of the associated circuit to energize and deenergize the associated coil, said circuit controlling mechanisms being responsive on the energization of all but one of the coils of the first group to maintain the intermediate spring connected to the upper magnetic element in the circuit controlling mechanisms surrounded by said coils, said circuit controlling mechanisms being responsive on the subsequent energization of a coil of the second group for attracting the magnetic spring to the lower magnetic element in the opening surrounded by said energized coil of the second group and the coil of the first group not energized, and responsive on the energization of the coil of the first group not previously energized to maintain the magnetic spring connected to the lower magnetic element at the opening surrounded by said coil of the first group and the coil energized in the first group, while the coil of the second group and the first energized coils of the first group may be deenergized, the energization of the coil of the first group remaining energized being suflicient to maintain the contact spring connected to the lower magnetic element in the above-mentioned opening, the remaining circuit controlling mechanisms and the energizing and deenergizing of the coils in this manner enabling the subsequent establishing of connective changes through the circuit controlling mechanisms at other crosspoints of the two groups of coils without such energizations and deenergizations interfering with the maintaining of the connection at the first-mentioned opening or be interfered with by the energized condition of said first-mentioned coil remaining energized.

GEORGE R. STIBITZ. 

